Bribe Sand Worms for 900000 to receive 15 Winning Formulas.

Healing Waters:
Steal Common from Adamantoise (1x)
Bribe Anacondaur for 116000 (16x)

Dark Matters:
Drop Rare from Area/Species Bosses in Monster Arena.
99 for unlocking Ultima Buster

You don't need much Dark Matter (unless you're playing PAL and need Ribbon) because Ultimate Weapons come powered up with Break Damage Limit. But if you max out the Sphere Grid, you'll pick up a lot of Dark Matter in the process from fighting all those Species bosses a bunch of times.